Polystyrene plastic compositions containing bis-phenoxy flame retardants

ABSTRACT

PLASTIC COMPOSITIONS CONTAINING POLYSTYRENES AND BISPHENOXY COMPOUNDS HAVIN THE FORMULA:   ((A)I,(Z)M-PHENYL)-O-(ALKYLENE)-O-((A)I&#39;&#39;,(Z)M&#39;&#39;-PHENYL)   WHEREIN Z IS BROMINE, M AND M&#39;&#39; AR INTEGERS HAVING A VALUE OF 1-4, I AND I&#39;&#39; ARE INTEGERS HAVING A VALUE OF 1 OR 2, ALKYLENE IS A STRAIGHT OR BRANCHED CHAIN ALKYLENE GROUP HAVING FROM 1 TO 6 CARBON ATOMS AND A IS CYANO, NITRO, LOWER ALKOXY, LOWER ALKYL, FLUORINE, DIALKYL AMINE, PHENYL, HALO-PHENYL, BENZYL OR HALO-BENZYL.

United States Patent 3,833,538 POLYSTYRENE PLASTIC COMPOSITIONS CON- TAINING BIS-PHENOXY FLAME RETARDANTS Arnold L. Anderson, Alma, Mich., assignor to Michigan Chemical Corporation, St. Louis, Mich.

No Drawing. Continuation-impart of abandoned applicatron Ser. No. 260,240, June 6, 1972. This application 'Feb. 8, 1973, Ser. No. 330,822 The portion of the term of the patent subsequent to May 14, 1991, has been disclaimed Int. Cl. C08f 45/60 U.S. Cl. 260-45.9 R 17 Claims ABSTRACT OF THE DISCLOSURE Plastic compositions containing polystyrenes and bisphenoxy compounds having the formula:

. Q A v zm@onk iene -o@ wherein Z is bromine, m and m are integers having a value of 1-4, iand i are integers having a value of l or 2, alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms and A is cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkyl amino, phenyl, halo-phenyl, benzyl or halo-benzyl.

This application is a continuation-in-part of copending application Ser. No. 260,240, filed June 6, 1972 and now abandoned. The entire specification of this case, Ser. No. 260,240, is to be considered as incorporated herein by reference.

I The prior art considered in conjunction with the preparation of this application is as follows: U.S. 2,130,990; U.S. 2,186,367; U.S. 2,329,033; U.S. 3,666,692; U.S. 3,686,320; U.S. 3,658,634; German Pat. No. 1,139,636; German Pat. No. 2,054,522; Japanese Pat. No. (72) 14,- 500 as cited in Volume 77, Chemical Abstracts, column l53737k (1972); Chemical Abstracts, Volume 13, column 448 ;Chemical Abstracts, Volume 31, column 7045 and Journal of the Chemical Society, pages 2972-2976 (1963). All of these publications are to be considered as incorporated herein by reference.

The present invention relates to plastic compositions containing polystyrenes. More specifically, the present invention covers plastic compositions containing polystyrenes and certain bis-phenoxy compounds (hereinafter defined) as flame retardants for said plastic compositions.

Polystyrenes and utility thereof are known in the art as exemplified by Polystyrene, W. C. Teach and G. C. Kiessling (Reinhold Plastics Applications Series), Reinhold Publishing Corporation, New York, 1960 and Modern Plastics Encyclopedia 1972-1973, Vol. 49: No. 10A, Octobet-1972, pages 97-99, 161 and 271-272 and which publications are in toto incorporated herein by reference.

The need for flame retarding polystyrenes has also been recognized in the art as exemplified by U.S. 3,347,822 and U.S. 3,422,048 and Modern Plastics Encyclopedia, ibid, pages 221, 222 and 456-458 and which publications are in toto incorporated herein by reference.

The resultant disadvantages in the utilization of various prior art materials as flame retardants for polystyrenes include, without limitation, factors such as thermal migration, heat instability, light instability, non-biodegradable,

toxicity, discoloration and the large amounts employed in order to be effective.

Thus, there is always a demand for a material which will function as a flame retardant in polystyrenes and concurrently will not, by incorporation therein, adversely effect the chemical and/ or physical and/ or mechanical properties of the resultant polystyrene plastic composition.

The prior art problem of providing a flame retarded polystyrene composition having desired chemical, physical and mechanical properties has now been substantially solved by the present invention and the above-described disadvantages substantially overcome.

Accordingly, one of the main objects of the present invention is to provide polystyrene plastic compositions which are flame retarded.

Another object of the present invention is to provide a material for polystyrene plastic compositions which will not substantially adversely effect the chemical and/or physical and/or mechanical properties of said compositions.

A further object of the present invention is to provide a flame retardant which is economic and easy to incorporate into polystyrene plastics without being degraded or decomposed as a result of blending or processing operations.

It has been found that the foregoing objects can be obtained by the incorporation of a new class of bis-phenoxy compounds in polystyrenes to subsequently provide flame retarded compositions which exhibit outstanding chemical, physical and mechanical properties.

The bis-phenoxy compounds used in the present invention compositions have the formula:

In Formula I above, Z is bromine; m and m are integers each independently having a value of 1-4; i and i are integers each independently having a value 'of 1 or 2; alkylene is a straight branched chain alkylene group having from 1 to 6 carbon atoms (e.g. CH C H C H C4Hg, C5H10, C6H12 and and A is from the group cyano (-CH), nitro (NO lower alkoxy (e.g. OCH OC H lower alkyl (e.g. CH C H CgHq, C H fluorine, dialkylamino e.g. -N(CH -N(C H phenyl (C H halo-phenyl, benzyl (CH C H and halo-benzyl.

In Formula I, i or i is 1 when m or m is 4, respectively. It is to be understood that all of the compounds falling within the above Formula I and as heretofore defined are generically described herein as bisphenoxy compounds.

Illustrative (but without limitation) of some of the present invention bis-phenoxy compounds are shown below:

the exemplary definitions of A, Z, i, i, m, m and alkylene are listed in Table I.

CHzCH(CHa)CHzCH2 on 7 TABLE I Z m m A z i Alkylene Compound number:

2 2 CN 1 1 CH2 2 2 F 1 1 C2H4 2 2 'CN 1 1 CsHa 2 2 CN 1 1 02H; 2 2. .NO: 1 1 C2114 2 2 -OCH: 1 1 C2114 3 3 --OCH3 1 1 C2134 2 2 CH3 1 1 C2114 2 2 F 1 1 C3110 2 2 N (CH3): 1 1 02H; 2 2 CaH5 1 1 CzI-It 2 2 CeH3B1z 1 1 C2114 2 2 -CH2C0H5 1 1 CzHA A 2 2 CH2COH3BI2 1 1 C2114 3 3 CeH3Cl2 l 1 C311 3 3 F 1 1 CsHtz 2 2 --CN 2 2 C2114 4 4 -CN 1 1 CaHtt 3 3 C6H2Bl'3 1 1 C2H4 3 3 NO2 2 2 CgHs 2 2 CN 1 1 CH(CH CH2 4 4 N0g 1 1 CH(CH3) CHzCIIz 3 3 F 2 2 1 1 --C4Ho 1 1 2 1 1 OC4H9 1 1 0211 In general, the bis-phenoxy compounds are prepared 1 metals are potassium and sodium. Where one desires to t increase, for example, ease of handling the reaction mass, solvents such as ketones (e.g. acetone, methyl ethyl ketone, and methyl iso-butyl ketone), alcohols (e.g. methanol, ethanol, iso-propyl alcohol, butyl alcohol and glycols), or aqueous solvents (e.g. water, a mixture of water and alcohol and a mixture of water and ketone) can be employed. The desired end product, i.e. the bis-phenoxy compound, can be recovered from the reaction mass via various methods such as distillation or crystallization. Where the end product requires recovery via crystallization, various aromatic solvents such as benzene, toluene, xylene, dichlorobenzene and the like can be used.

Specifically, the bis-phenoxy compounds are prepared according to the following reactions:

(II) (III) A i A i 2HX Z m- 6 0 (alkylene) ow Z In the above reaction, X is halogen, preferably chlorine and alkylene is the same as herein defined. Where in and m' and i and i are different integers, then equivalent molar portions of the particular halogenated phenol are used with equivalent portions of dissimilar halogenated V W phenol.

The above reaction is conducted at temperatures ranging from the freezing point of the initial reaction mass to the boiling point thereof. Preferably the temperatures are from about 40 C. to about 200 C. and more preferably from about 50 C. to about 175 C. It is to be understood that the reaction can be conducted under sub-atmospheric (e.g. i A atmospheres), atmospheric or super-atmospheric (e.g. 1.5-10 atmospheres) pressure. Preferably, the reaction is carried out at atmospheric pressure.

The above-described processes can be carried out with conventional, readily available chemical processing equipment. For example, a conventional glass-lined vessel provided with heat transfer means, a reflux condenser and a mechanical stirrer can be advantageously The amount of bis-phenoxy compound employed in the present invention compositions is "any quantity which will effectively render the polystyrene containing composition flame retardant. In general, the amount used is from about 1% to 25% by weight, based on the total weight of the composition. Preferably, the amount employed is from about 5% to about"20% by, weight. It is to be understood that any amount can, be-used'as long as it does not substantially adversely affect the chemical and/or physical and/or mechanical properties of the end polymer composition. The amount 'utilizedf'h'owever, is such amount which achieves'theobjectivesde scribed herein. i i

It is to be understood that the term polystyrene as used herein means polymers containing more than 60% styrene (phenylethylene, vinyl benzenefstyrol," cinnamene) C H CH=CH or other unsaturated aromatic monomers comprised of variously substituted styrene derivatives. This term also includes rubber modified impact-resistant polystyrene and styrene-accrylonitrile .copolymers (sometimes referred to in the trade as SA :or

Thus the polystyrene in the invention compositions is any polystyrene herein defined and Which one so desires to flame retard. It is to be understood that :the: polystyrenes used can be a virgin material, i.e substan tially free of additives such as stabilizers, plasticizers, dyes, pigments, fillers, and the like, or. the polystyrenes can have additives (such as those mentioned andg'described herein) already contained therein or addedconcurrently with or after the addition of the. bis-phenoxy compounds. I ,1 1

Another facet of the present invention relates .to the use of certain metal compounds with-the bis-phenoxy compounds to promote a cooperative eflect therebetween and thus enhance the flame retardancy of the resultant plastic composition as compared to the flame retardancy of either one component used separately. These enhancing agents are from the group antimony, arsenic, bismuth, tin and zinc-containing compounds. Without; limi-t tation, examples of saidv enhancing agents include Sb O SbCl SbBr SbI ,SbOCl, As O As O ZnBO BaB 'O -H O, 2-ZnO-3B O -3-5H O and stannousoxide hydrate. The preferred enhancing agentis antimony tri-l oxide. 1

The amount of enhancing agent employed in'the present invention compositions is any amount which when used with said bis-phenoxy compounds 'will 'pro'mote acoop erative effect therebetween. In general, the amount em; ployed is from about 1% to about 15%, prereratny-frem about 2% to about 10%, by'weight, basedou'the" total weight of plastic composition. Higher amounts can b' used as long as the desired end result is achieved. V

It is also within the scope of the present invention to employ other materials in the present invention compositions where one so desires to achieve a particular end result. Such materials include, without limitation, adhesion promotors; antioxidants; antistatic agents; antimicrobials; colorants; flame retardants such as those listed on pages 456 158, Modern Plastics Encyclopedia, ibid, (in addition to the new class of flame retardants described herein); heat stabilizers; light stabilizers; pigments; plasticizers; preservatives; ultraviolet stabilizers and fillers.

In 'this latter category, i.e. fillers, there can be mentioned without limitation, materials such as glass; carbon; cellulosic fillers (wood flour, cork and shell flour); calcium' carbonate (chalk, limestone, and precipitated calcium carbonate); metal flakes; metallic oxides (aluminum, beryllium oxide and magnesia); metallic powders (aluminum, bronze, lead, stainless steel and zinc); polymers (comminuted polymers and elastomer-plastic blends); silica products (diatomaceous earth, novaculite, quartz, sand, tripoli, fumed colloidal silica, silica aerogel, wet process silica); silicates (asbestos, kaolimite, mica, nepheline syenite, talc, wollastonite, aluminum silicate and calcium silicate); and inorganic compounds such as barium ferrite, barium sulfate, molybdenum disulfide and silicon carbide.

The above mentioned materials, including fillers, are more fully described in Modern Plastics Encyclopedia, ibid, and which publication is incorporated herein (in toto) by reference.

The amount of the above described materials employed in the present invention compositions can be any quantity which will not substantially adversely afiect the desired results derived from the present invention compositions. Thus, the amount used can be zero (0) percent, based on the total weight of the composition, up to that percent at which the composition can still be classified as a plastic. In general, such amount will be from about 0% to about 75% and specifically from about 1% to about 50%.

. The bis-phenoxy compounds can be incorporated into the polystyrenes at any processing stage in order to prepare the present invention compositions. In general, this is undertaken prior to fabrication either by physical blending or during the process of forming polystyrenes per se. Where one so desires, the bis-phenoxy compounds may be micronized into finely divided particles prior to incorporation into the polystyrenes.

EXAMPLE I A polystyrene plastic material (Union Carbide TMDE 6500, a high impact polystyrene product free of additives) is utilized as the base resin in order to prepare 26 formulations (plastic compositions). With the exception of formulation No. l, the particular bis-phenoxy compound (and the antimony trioxide enhancing agent where indicated) is incorporated into the plastic by adding both to a Brabender mixer (Plastic-Corder, Torque Rheometer, Model PLV-150, C. W. Brabender Instruments Inc., South Hackensack, NJ) The mixer is equipped with a pair of roller type blades positioned within a head provided with heat transfer means.

The resultant mixture is heated to about 245 C.; at this temperature, it is in a molten state. The percentages by weight of each component utilized in the respective formulations are listed in Table 11. Each formulation is discharged from the mixer and upon cooling solidifies and is ground into chips. The chips are subjected to compression molding in a Wabash press by placing said chips between two platens, the bottom of which contains four equal size depressions three inches by five inches by /s inch deep. The top platen is then placed over the bottom platen and heat transfer means supplied thereto in order to melt said chips and thus provide solid samples (after cooling) for testing.

Portions of the solid samples of each respective formulation (Nos. 1-26) prepared according to the above de- 6 scribed procedure are then subjected to two diiferen standard flammability tests, i.e. UL 94 and ASTM D 2863-70. The UL 94 is, in general, the application of a burner to a test specimen (strip) for a certain period of time andobservation of combustion,'burning, and extinguishment. This procedure is fully set forth in Underwriters Laboratories bulletin entitled UL 94, Standard for Safety, First Edition, September 1972 and which is incorporated herein by reference. ASTM No. D2863- -70 is a flammability test which correlates the flammability of a plasticspecimen to the available oxygen in its immediate environment; this correlation is stated as an Oxygen Index, 01., level predicated upon the percent oxygen in the gaseous medium which is required to just provide a steady state of continuous burning of the plastic specimen. This ASTM method is fully described in 1971 Annual Book of ASTM Standards-Part 27, published by the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pa.; this publication is to be considered as incorporated (in toto) herein by reference.

The results of these flammability tests are shown in Table II.

Bls- Comphenoxy pound, number percent Enhancing Oxygen agent SbaOs, index,

percent percent UL 114 Formulationnum- 0 0 18.0 Burns 1 20 0 22.5 SB 1 20 10 28.5 SE4 2 20 0 23.0 SD 2 20 10 28.0 SE-l. 5 20 0 23.5 SB 5 20 10 31.0 SE-l 7 20 0 24.0 SB 7 2o 10 32.0 SE0 8 20 0 21.5 SB 8 20 10 28.5 813-1 10 20 0 22.0 SB 10 20 10 28.5 SE-l 12 20 0 23.0 SB 12 20 10 31.5 815-0 14 20 0 23.5 SB 14 20 10 31.0 813-1 10 20 0 23.0 SB 16 20 10 30.5 BE-1 18 20 0 24.5 SB 18 20 10 32.0 SE-O 21 20 0 22.5 SB 21 20 10 29.0 812-1 22 20 0 25.0 SB 22 20 10 32.5 SE-O 23 20 10 32.0 SE-O Referring to Table II, the bis-phenoxy compound number relates to the structural formulae heretofore set forth in Table I; a difference of 2% in the Oxygen Index values is considered significant; and the UL 94 values are on a graduated scale wherein the highest degree to lowest degree of flame retardancy is respectively SE-0, 815-1, 815-2, SB and Burns.

The results shown in Table II demonstrate the unique effectiveness of these bis-phenoxy compounds as flame retardants for polystyrene. Specifically, Formulation No. 1 (the control) had an 0.1. of 18.0 and UL 94 value of Burns. In Nos. 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24, the use of the particular bis-phenoxy compound results in a significant increase (3.5-7.0%) in fire retardancy as measured by 01. (While these formulations had a SB rating, UL 94, the individual U.L. rating had a wide range of values and thus the- 0.1. number is, in this case, more indicative of increased flame retardancy.)

The use of an enhancing agent such as Sb 0 to promote a cooperative elfect between such agent and the bis-phenoxy compound is fully demonstrated via the results obtained from Formulation Nos. 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25 and 26. The highest UL 94 ratings and significantly higher 01. values (9.5-14.5% increase) are obtained.

20.%/ levels of Example I.

Y EXAMPLE 1n 1 Portions of the solid samples of Formulation Nos. 1-26 preparedac cording to the above described procedure of ExampleI are subjected to the following ASTM tests in order to ascertain other properties of the resultant plastic composition:

(1) Tensile Strength (at break): ASTM Test No. D638- (2) Flexural Strength: ASTM Test No. D790-63;

(3) Flexural Modulus: ASTM Test No. D790-63;

(4) Notched Izod Impact: ASTM Test No. D25 6-5 6; and

(5) Heat Distortion Temperature (HDT): ASTM Test NO. D64856.

Each of the aforementioned ASTM tests are standard tests in the art and are utilized collectively in order to ascertain the efficacy of a polymeric system as an overall flame retarded composition for commercial application. All of these ASTM Tests are to be considered as incorporated herein by reference. I The results of these ASTM tests show that the physical properties of the presentinvention compositions are basically thersame (except 0.1 and UL 94 values) as the plastic material without the flame retardant (i. e. Formulation No. 1). Thus, there is no substantial adverse effect on the physical properties of the plastic material when the novel compounds are incorporated therein.

EXAMPLE IV The procedure of Examples I, II and III are repeated except that the enhancing agent used is zinc borate instead of Sb O Substantially the same results are obtained using zinc borate as those obtained using Sb O The other metal containing compounds are found to be equally effective.

In view of the foregoing Examples and remarks, it is seen that the plastic compositions, which incorporate these compounds, possess characteristics which have been unobtainable in the prior art. Thus, the use of these compounds in the above described plastic material as flame retardants therefore is quiteunique'since it is not'possible to predict the effectiveness and functionality of any particular material in any polymer system until it is actively undergone incorporation therein and the resultant plastic composition tested according to various ASTM Standards. Furthermore, it is necessary, in order to have commercial utility, that theresultant flame retarded plastic composition pos- 'sess characteristics such as being non-toxic. Use of these compounds in the plastic material has accomplished all of these objectives. The above examples have been described in the foregoing specification for the purpose of illustration and not limitation. Many other modifications and ramifications will naturally suggest themselves to those skilled in the art based on this disclosure. These are intended to be comprehended as within the scope of this invention.

What is claimed is: I

I 1. A plastic composition containingapolystyrene 1 incorporated therein an effective amount of a-flarnefreltardant which is a bis-phenoxy compound having the for-;

mula:

wherein Z is bromine; m and m are-integers having a value of 1-4; and i and i are integers having a value of'l or 2; alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms; and A is selected from the group consisting of cyano, nitro, loweralkoxy; lower alkyl, fluorine, dialkylamino, phenyl, halo-phenyl; benzyl, or halo-benzyl, with the proviso that when mor m is 4, i or i respectively is 1. Y 2. The composition as set forth in claim 1 wherein i and i are both 1. 3. The composition as set forth in claim l wherein i and i'areboth2. 4. The composition as set forth in claim 2 wherein A is cyano.

5. The composition as set nitro.

6. The composition as set forth in claim 2 'wherein'A is lower alkoxy. 7. The composition as setforth in claim 2 wherein A is lower alkyl. 8. The composition as set forth fluorine. I

9. The composition asset forth in claim 2 wherein A is dialkylamino.

10. The composition as set forth is phenyl. v 11. The composition as set forth in claim 2 wherein 'A is halo-phenyl.

12. The composition is benzyl. 13. The composition as set forth in claim 2 wherein A is halo-benzyl. i

14. The composition as set forth alkylene is CH 15. The composition as set alkylene is C H 16. The composition as set forth in claim I wherein alkylene is C H v 17. The composition as set forth in claim 1 wherein alkylene is C H References Cited STATES, PATENTS l forth in claim 2'wherein A is in claim a wherein Art in claim 2 wherein as set'fort h in claim 2 whereinA in claim 1 wherein forth in claim 1 wherein UNITED 3,658,634 4/1972 Yanagi et al. 161-403 3,717,609 2/1973 Kutner 260-459 G 2,329,033 9/1943 Briton et al. 260 -332. R 3,385,819 5/1968 Gouinlock '260'45.75-"R 3,560,441 2/1971 Schwarcz et al. 26045.7 R

MAURICE I. WELSH, Primary Examiner US. 01. X.R. A

260-41 R, 41 A,41 B, 41 GA R 

